Test tube rack



FIG. 1 is a top plan view of a test tube rack showing our new design.

FIG. 2 is a front elevation view thereof.

FIG. 3 is a side elevation view thereof; and

FIG. 4 is a cross sectional view taken along lines 4--4 of FIG. 2.

The undisclosed side and rear portion of the rack are mirror images of the respective side and front shown. The broken lines are shown for illustrative purposes only. 

The ornamental design for a test tube rack, substantially as shown and described. 